SecretMessage is an offline-friendly browser tool that encrypts text and optional photos directly on your device using AES-256-GCM. Your content is processed locally in your browser and is not uploaded to a server.
SecretMessage helps you encrypt content before you send it through platforms such as WhatsApp, Telegram, Email, Instagram DM, Signal, Discord, or other copy-and-paste friendly channels. Instead of sending plain text, you send an encrypted block that can only be opened with the same key.
Yes. SecretMessage is built as an offline-friendly web app. After loading the site, core files may remain available on your device through browser caching and service worker support. You can also save the project files to your computer and open the app locally in a browser for personal offline use.
Open the Encrypt tab. Write your message and optionally add a photo. Then choose your own key or use 🔑 Generate. Click Encrypt → Create Encrypted Block to generate a single encrypted block.
You can copy the encrypted block and paste it into WhatsApp, Telegram, Email, Instagram DM, Signal, Discord, or similar platforms. If you included a photo, the encrypted block may become large. In that case, downloading it as a text file and sending it as a document or file is usually the most reliable option.
The recipient opens the Decrypt tab, pastes the encrypted block, and enters the same key. If the key is correct, the original message and optional photo are revealed. If the key is wrong or the block was altered, decryption fails because AES-GCM verifies integrity.